Hi manfred,
it seams i made an error, it is not the 610 but a 660
and this what i found as info, thx
Technical Data
Rated power: 100 W
Power Outlet Impedances : 4, 8 or 16 ohms
Minimum Input level: - 40 dB
Maximum Input Level: - 3 dB
Effects loop: SEND - 10 dB (average), - 3 dB (max.)
RETURN + 3 dB (max.)
LINE output: + 3 dB (max.)
Levels are based on 0db => 1 V eff, measured at 1kHz.
Tubes: V1 -> ECC83/7025 F.Q. (First Quality)
V2, V3, V4, V5 -> ECC83/12AX7 selected
V6 -> ECC83/12AX7 standard
V7, V8, V9, V10 -> 5881 or 6L6 GC matched set
Fuses: AC mains: 230 Volts 100 and 120Volts
external 2,5 AM 5 AM (medium)
internal 3,15 AT 6,3 AT (slow)
Power tubes (ECS): 4 x 160 mAM